Vehicle stabilization system and/or method

ABSTRACT

The system can include: a vehicle 100 and a stabilizer 200. However, the system can additionally or alternatively include any other suitable set of components. The system functions to facilitate vehicular transport (e.g., via a cabin). Additionally, the system can provide impact attenuation and/or mitigate rebound of the vehicle during a water landing. Additionally or alternatively, the system can function to provide aquatic stabilization of the vehicle and/or cabin thereof. However, the system 100 can provide any other suitable functionalities.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.63/422,851, filed 4 Nov. 2022, and U.S. Provisional Application No.63/390,398, filed 19 Jul. 2022, each of which is incorporated herein inits entirety by this reference.

TECHNICAL FIELD

This invention relates generally to the aerospace field, and morespecifically to a new and useful vehicle stabilization system and/ormethod in the aerospace field.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic representation of a variant of the system.

FIG. 2 is a trimetric view of a variant of a stabilizer.

FIGS. 3A and 3B are a first and second side view cross-section of avariant of the system, respectively.

FIGS. 4A, 4B, and 4C are a first, second, and third schematic example,respectively, of a variant of the system.

FIG. 5 is a diagrammatic example of a variant of a stabilizer.

FIG. 6 is a schematic representation of a variant of the system.

FIGS. 7A-7D are diagrammatic representations of a variant of the systemin various stages of a water landing.

FIG. 8 is a diagrammatic example of a variant of the system.

FIG. 9 is a diagrammatic example of a variant of the system.

FIGS. 10A-10B are a first and second trimetric view and a variant of thestabilizer, respectively.

FIG. 11 is a partial 3D view of and a variant of the system.

FIGS. 12A-12B are a first and second example of a stabilizer,respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the inventionis not intended to limit the invention to these preferred embodiments,but rather to enable any person skilled in the art to make and use thisinvention.

1. Overview.

The system, an example of which is shown in FIG. 1 , can include: avehicle 100 and a stabilizer 200. However, the system can additionallyor alternatively include any other suitable set of components. Thesystem functions to facilitate vehicular transport (e.g., via a cabinno). Additionally, the system can provide impact attenuation and/ormitigate ‘rebound’ of the vehicle and/or cabin during a water landing.Additionally or alternatively, the system can function to provideaquatic stabilization of the vehicle 100 and/or cabin 110. However, thesystem 100 can provide any other suitable functionalities.

The system is preferably integrated with a vehicle system 10 (e.g., anaerial vehicle, such as a balloon vehicle) and/or other enclosure, morepreferably a vehicle or enclosure configured to contain one or moreliving occupants, such as human occupants. For example, the systemand/or method can be used with a pressure vessel capsule 11 (e.g.,examples are shown in FIG. 4A, FIG. 4B, and FIG. 4C; where the cabin isintegrated into the pressure vessel capsule 11; etc.) configured totransport human occupants to high altitudes (e.g., approximately 100,000feet; via a propulsion module 12, an example of which is shown in FIG.4A). However, the system 100 can include or operate in conjunction withany other suitable vehicle systems, and/or without separate vehicle orpropulsion systems (e.g., when released for water landing; etc.).

In some variants, the system, method, vehicle (e.g., aerial vehicle,such as a balloon vehicle) and/or enclosure in which the system and/ormethod are integrated and/or employed, and/or any other suitableelements thereof can include one or more aspects such as described inU.S. patent application Ser. No. 17/160,837, filed 28Jan. 2021 andtitled “AEROSPACE VEHICLE SYSTEM AND METHOD OF OPERATION”, U.S. patentapplication Ser. No. 17/162,151, filed 29 Jan. 2021 and titled“AEROSPACE BALLOON SYSTEM AND METHOD OF OPERATION”, U.S. patentapplication Ser. No. 17/164,668, filed 1 Feb. 2021 and titled “AEROSPACEBALLOON SYSTEM AND METHOD OF OPERATION”, and/or U.S. patent applicationSer. No. 17/165,814, filed 2 Feb. 2021 and titled “AEROSPACE BALLOONSYSTEM, PARACHUTE, AND METHOD OF OPERATION”, each of which is hereinincorporated in its entirety by this reference. For example, the systemcan include a balloon and a capsule tethered to the balloon (e.g., atthe top of the capsule, such as by a set of mounts at a superior surfaceof the capsule, etc.).

The term “substantially” as utilized herein can mean: exactly,approximately, within a predetermined threshold or tolerance, and/orhave any other suitable meaning.

The term ‘rebound’ or the equivalent term ‘bounce-back’ as utilizedherein, in conjunction with vehicular water impacts or otherwise, canrefer to a physical phenomenon which may result from a buoyant object(e.g., net density or net effective density less than that of water;configured to float in water on Earth at sea level) contacting thesurface of a body of water while traveling with an initial positivevelocity component in the direction of a weight vector (e.g., travelingdownward). In such circumstances, the object may ingress the body ofwater (e.g., relative to the surface prior to contact; displacing thewater to occupy a space previously occupied by the water; etc.) below anequilibrium depth of static stability (a.k.a., “draft” depth for theobject; depth at which buoyancy force balances weight in a state ofstatic equilibrium/stability), overshooting the equilibrium depth as aresult of the initial kinetic energy of the object traveling (downward)with the initial velocity component (and potential energy of the objectassociated with height of the object above the draft depth), an exampleof which is shown in FIG. 8 . The dynamics of this behavior may resemblethat of an underdamped spring-mass system, where the buoyancy (buoyantforce) on the object behaves like a spring (spring force) as a functionof object depth, resulting in the object ‘bouncing back’ or ‘rebounding’relative to the surface of the water upon initial contact. As anexample, with a sufficiently large initial velocity, some objects (e.g.,a basketball; etc.), may rebound with sufficient energy to launch awayfrom the surface of the water. As a second example, other objects (e.g.,buoys) may oscillate around the equilibrium draft depth, bobbing up anddown repeatedly until friction/drag dampens the dynamic response (e.g.,dissipating the initial kinetic and gravitational potential energy). Ina third example, rebound effects may grow increasingly pronounced asobjects (e.g., of similar geometry) increase in size (e.g., volumeincreases relative to surface area for increasingly large objects; asmay be otherwise beneficial for increasing passenger/payload capacityand/or window viewing areas) and/or decrease in density (e.g., as may beotherwise advantageous for mass optimizations). However, the terms‘bounce-back’ and/or ‘rebound’ may be otherwise suitably referencedherein, and/or may refer to any other suitable behaviors or physicalphenomena.

2. Benefits.

Variations of the technology can afford several benefits and/oradvantages.

First, variations of this technology can provide impact attenuation byreducing initial shock loads associated with vehicle deceleration. Suchvariants can utilize nadir structures, such as a stabilizer (e.g.,conic, aerodynamic/hydrodynamic, etc.), to lengthen a duration ofinitial contact and/or a depth of water penetration during a waterlanding, which may reduce shock upon water impact. Variants canadditionally allow water ingress into a nadir structure(s) during waterlandings, which may further increase the depth of initial waterpenetration (e.g., delaying and damping the dynamic effects of vehiclebuoyancy). However, variants can otherwise provide impact attenuation.

Second, variations of this technology can mitigate the effects ofvehicle rebound during a water landing by utilizing a stabilizer whichallows water ingress (e.g., flooding) to increase resistance to reboundmotions. For example, the stabilizer may increase hydrodynamic drag(e.g., particularly when flooded with water; acting as a sea-anchor)and/or may provide resistance to vertical motion (e.g., damping reboundeffects). However, variants can otherwise mitigate the effects ofvehicle rebound and/or otherwise facilitate water landings.

Third, variations of this technology can facilitate water landing,impact attenuation, and/or rebound mitigation under a variety ofincidence angles and/or vehicle trajectories. For instance, when landingunder prevailing winds, the vehicle may be angled relative to gravityand/or may have a nonzero horizontal velocity component. Some variantsmay facilitate angled and/or partially transverse landings by includinga substantially rotationally symmetric (e.g., conic) stabilizer with anadir cone angle between 60 and 100 degrees (e.g., 70 degree cone; 90degree cone; etc.). In particular, low velocity landings, which may beotherwise desirable for impact mitigation, may be more sensitive toprevailing wind (e.g., where the wind speeds may exceed vertical speedof the descending vehicle), as the vehicle trajectory may. However,variants can otherwise facilitate water landings in various ambientconditions, and/or can be otherwise configured.

Fourth, variations of this technology can increase the stability of thevehicle and/or cabin when waterborne. For example, variants canstabilize the cabin with a primary (e.g., vertical) axis of the cabinaligned with a gravity vector and/or with a cabin standing platform(a.k.a., deck) substantially orthogonal to a gravity vector. Inparticular, this may improve experiences for cabin occupants whencompared to vessels which stabilize by tipping to lay sideways (e.g.,inhibiting the ability of users to stand or walk aboard the cabin whenwaterborne, which may not be well suited for vehicles with a degree ofrotational symmetry). However, variants can otherwise provide cabinstability.

Fifth, variations can facilitate water landings of spacecraft orstratospheric aircraft with large (e.g., human-scale) viewing windows,which can offer superior, more immersive viewing opportunities and animproved trip experience for vehicle occupants. However, variants canfacilitate water landings of any suitable vehicle systems, and/or mayoperate with any suitable vehicles.

However, variations of the technology can additionally or alternatelyprovide any other suitable benefits and/or advantages.

3. System.

The system, an example of which is shown in FIG. 1 , can include: avehicle 100 and a stabilizer 200. However, the system 100 canadditionally or alternatively include any other suitable set ofcomponents. The system functions to facilitate vehicular transport via acabin. Additionally, the system can provide impact attenuation and/ormitigate rebound of the cabin during a water landing. Additionally oralternatively, the system can function to provide aquatic stabilizationof the cabin. However, the system 100 can provide any other suitablefunctionalities.

3.1 Vehicle.

The vehicle 100 functions to facilitate vehicular transport via a cabin102. Additionally or alternatively, the vehicle 100 can function tomount and/or structurally support the stabilizer 200. The vehicle ispreferably an aerospace vehicle, such as the capsule of alighter-than-air vehicle, but can additionally or alternatively be anaircraft, watercraft, spacecraft, cargo-vehicle, (manned) passengervehicle, unmanned vehicle, and/or any other suitable vehicle. Invariants, the vehicle can be the vehicle and/or capsule as described inU.S. patent application Ser. No. 17/160,837, filed 28 Jan. 2021 andtitled “AEROSPACE VEHICLE SYSTEM AND METHOD OF OPERATION”, U.S. patentapplication Ser. No. 17/162,151, filed 29 Jan. 2021 and titled“AEROSPACE BALLOON SYSTEM AND METHOD OF OPERATION”, U.S. patentapplication Ser. No. 17/164,668, filed 01Feb. 2021 and titled “AEROSPACEBALLOON SYSTEM AND METHOD OF OPERATION”, and/or U.S. patent applicationSer. No. 17/165,814, filed 02Feb. 2021 and titled “AEROSPACE BALLOONSYSTEM, PARACHUTE, AND METHOD OF OPERATION”, each of which is hereinincorporated in its entirety by this reference.

The vehicle can be substantially rotationally symmetric (e.g., about aprimary axis of the vehicle and/or stabilizer), but can additionally oralternatively be asymmetric, include asymmetric features (e.g., ahatch), and/or can be otherwise configured. The vehicle can include ordefine a vehicle platform (e.g., deck, mounting platform for the humansupports, etc.), which is orthogonal to a primary (vertical) axis of thevehicle. As an example, the vehicle and/or stabilizer can besubstantially rotationally symmetric about a primary axis which isoriented substantially vertically during vehicle traversal (e.g., absentwind effects; during ascent and/or landing; while the vehicle iswaterborne; in all modes of operation; etc.). However, the vehicle canbe otherwise configured.

The vehicle 100 can optionally include a cabin 102. The cabin canfunction to carry occupants (e.g., live occupants such as live humans)within the vehicle and to maintain conditions necessary for occupanthealth, safety, and/or comfort. The cabin is preferably arranged withinthe vehicle interior, such as within a pressure vessel interior (e.g.,wherein the pressure vessel maintains a breathable atmosphere inside thepressure vessel interior, even in low-pressure environments unsuitablefor sustaining human life). The cabin can include one or more humansupports (e.g., seats). Each human support is preferably configured toorient a human occupant (e.g., the face and/or eyes of the occupant)toward a window of the pressure vessel (e.g., toward the window closestto the human support). For example, each human support can be arrangedbetween the central axis and a window (preferably a different window foreach human support). In this example, the human supports (e.g., seats)are preferably arranged facing the respective window with which they arealigned, but can additionally or alternatively have any other suitablearrangement. In a specific example, the cabin includes a set of seatsarranged around the cabin (e.g., regularly spaced around the cabin). Inthis specific example, each seat is preferably arranged (e.g.,mechanically secured to the capsule, such as to a floor of the cabin)near and facing toward a different window of the pressure vessel. In asecond example, a floor/deck of the cabin is substantially orthogonal toa primary axis of the capsule, wherein a balloon can be tethered at anupper end of the capsule (e.g., at a set of mounts; at a superiorsurface of the capsule; an example is shown in FIG. 4C), opposite thestabilizer along the primary axis.

However, the human supports can additionally or alternatively have anyother suitable functionality and/or arrangement, and/or the cabin canadditionally or alternatively include any other suitable elements in anysuitable arrangement.

3.2 Stabilizer.

The stabilizer, an example of which is shown in FIG. 2 , functions toattenuate impacts and/or mitigate ‘rebound’ of the vehicle during waterlandings. Additionally, the stabilizer can function to provide aquaticstabilization of the vehicle 100 and/or cabin 110.

The stabilizer can be conical (e.g., substantially conical, partiallyconical, pseudo-conical; truncated conical body, perforated/partialconical body, piecewise conical, etc.), hyperbolic, blunt (e.g., bluntbody shaped; at a nadir end), aerodynamic/hydrodynamic, tapered (e.g.,towards a nadir), and/or can have any other suitable geometry or includepartial elements or surfaces of any of the aforementioned geometricconstructions. In variants (e.g., examples are shown in FIGS. 3A and3B), the stabilizer can include a body shape with a geometry defined asa solid of revolution and/or an inferior surface which is a surface ofrevolution about a central axis (e.g., vertical axis of the stabilizer).For example, an inferior surface of the stabilizer can be defined byrevolving a path (generatrix) about a central axis (e.g., an example isshown in FIG. 9 ; revolving 360 degrees or less than 360 degrees, suchas for a body panel or region between apertures, etc.), where anendpoint of the generatrix lies along the central axis (e.g., at a nadirof the stabilizer) and the generatrix includes: a line segment (e.g.,having a zenith angle of about 30-50 degrees relative to the centralaxis, such as 30 degrees, 35 degrees, 45 degrees, etc.), a plurality ofline segments (e.g., a first line segment, proximal to the nadir, with azenith angle of about 35 degrees and a second line segment, distal fromthe nadir, with a zenith angle of about 45 degrees), a smooth path/curve(e.g., with no inflection points, with one inflection points, with morethan one inflection point, etc.; defined by a function with a continuousfirst derivative), and/or any other suitable elements. In a secondexample, the stabilizer includes a cone-shaped inferior surface, roundedat the nadir. In a third example, the stabilizer includes a firstconical surface smoothed with a second conical surface. In a fourthexample, the stabilizer includes a blunt body (e.g., as may haveadvantageous aerodynamic properties for atmospheric re-entry in somevariants of the system). In a fifth example, the stabilizer can becone-shaped with the cone angle widening towards a base end of the cone(e.g., distal the nose end of the cone; distal the nadir end of thecone). However, the stabilizer can have any other suitablegeometry/structure(s).

In one set of variants, the stabilizer can include and/or define: aninferior surface comprising a blunt nadir end and a truncated conicalsurface which is substantially radially symmetric about the primaryaxis.

The stabilizer is preferably narrower than the capsule and/or extendsacross only a partial fraction of the width of the vehicle capsuleand/or cabin thereof (e.g., wherein a width of the capsule is largerthan a maximum width of the stabilizer, such as evaluated at a maximumwidth of the capsule and/or largest cross section orthogonal to theprimary axis; wherein the stabilizer is mounted below plane of the cabinwith the largest cross section along the primary axis). For example, forsubstantially conical stabilizers, the maximum radius of the stabilizerabout the central axis can be about half of the maximum radius of thevehicle capsule about the central axis. However, the stabilizer can bethe same width as the vehicle capsule/cabin (e.g., spanning the fullinferior surface of the capsule), larger than a width of the vehiclecapsule (e.g., in a reference plane, such as at the lip/periphery of thecapsule; wherein the lip is offset from the aerospace capsule), and/orcan be otherwise configured.

In variants, the vehicle width can be larger than the vehicle height(e.g., including the stabilizer, excluding the stabilizer, etc.) and/orsubstantially similar to the vehicle height (e.g., width/height ratio ofless than 0.5, 0.5, 0.75, 0.8, 0.9, 0.95, 1.0, 1.05, 1.1, 1.25, 1.5, 2,greater than 2, etc., with the height evaluated as the length along theprimary axis), which may improve the stability upon impact and/or withthe vehicle waterborne (e.g., to avoid tipping). Additionally, the(effective) center of mass of the vehicle (e.g., including water masswithin the interior of the stabilizer) is preferably at or below thedraft height of the vehicle, which may improve the inherent stability ofthe vessel. However, the stabilizer can be employed with any othersuitable vehicle with any other suitable mass distribution and/or masscharacteristics (e.g., which may vary based on cargo arrangements, forexample).

The stabilizer can be connected/mounted to the vehicle by a set ofmounts. The stabilizer is preferably mounted to an inferior surfaceand/or nadir portion of the vehicle with the mounts arranged within aninterior of the stabilizer (e.g., between the cap and theperiphery/lip), however the stabilizer can additionally or alternativelybe externally mounted, mounted along a peripheral lip, mounted via theset of ribs, and/or otherwise mounted to the vehicle/capsule.

The stabilizer preferably includes and/or defines a set of apertures 202which function to facilitate water ingress during a water landing and/orfacilitate stabilization when the vehicle 100 is waterborne (e.g., uponlanding). The apertures preferably extend through a thickness of thestabilizer and fluidly couple an interior of the stabilizer to an(ambient) exterior. For example, the vehicle and the stabilizer cancollectively define a fluid interior, fluid reservoir, and/or fluidmanifold which extends between a superior surface of the stabilizer andan inferior surface of the vehicle body (e.g., underside of a pressurevessel), wherein the apertures fluidly couple the fluid manifold to theambient, fluid exterior through the thickness of the stabilizer (e.g.,at an inferior surface/underside of the stabilizer). The fluidmanifold/reservoir is preferably fluidly isolated from the cabininterior and/or a pressure vessel interior of the cabin, which canprevent water ingress into the cabin (e.g., as may beundesirable/unsuitable for the comfort of cabin occupants). As anexample, and offset between the lip of conical stabilizer and theaerospace capsule defines at least one aperture at the lip, wherein theconical stabilizer defines a fluid manifold between the plurality ofapertures through the thickness of the conical stabilizer and the atleast one aperture at the lip. As a second example, the fluid manifoldcan fluidly couple each of the apertures of the plurality (e.g., betweenthe stabilizer and an inferior surface of the vehicle capsule).

The set of apertures preferably includes a plurality of apertures, andcan include: less than 4, 4, 6, 8, 10, 12, 24, greater than 24, anyrange bounded by the aforementioned values, and/or any other suitablenumber of apertures. However, the set of apertures can alternativelyinclude a single aperture or define a unitary fluid manifold, and/or theset of apertures can include any other suitable number of apertures.Additionally or alternatively, in some variants, the system mayaltogether exclude apertures (e.g., where apertures may be selectivelysealed-off in one or more configurations; etc.). However, the system caninclude any other suitable number of apertures.

Apertures preferably define an aperture area, which can be defined as: aarea of relief relative to an inferior surface of the stabilizer; anarea of a vertical projection of the aperture(s); an area of anorthogonal projection of the aperture(s) relative to the central axis;an area of relief along reference surface defined by revolving ageneratrix of the stabilizer body (e.g., such as an inferior boundary ofa rib or body profile), about the central axis; and/or can be otherwisesuitably defined. In variants, the aperture area can be: less than 0.25m², 0.25 m², 0.5 m², 1 m², 2 m², 3 m², 5 m², 10 m², greater than 10 m²,any range bounded by the aforementioned values, and/or any othersuitable aperture area. The aperture area, as a proportion of theinferior surface area and/or vertically projected area of the stabilize,can be: less than 1%, 1%, 2%, 3%, 5%, 7%, 10%, 12%, 15%, 20%, 25%,greater than 25%, any open or closed range bounded by the aforementionedvalues, and/or any other suitable area proportional to the inferiorsurface area of the stabilizer. In an example, the plurality ofapertures defines an aperture area between 2% and 10% of an area of aninferior surface area of the stabilizer (e.g., which may providecombined impact attenuation and rebound damping; which may avoidsignificantly overdamping and/or underdamping nominal landings).Additionally or alternatively, in some variants, the aperture area canbe based on a combined-optimization of inferior surface area, structuralstrength, and/or water ingress resistance. For example, as the aperturearea approaches zero, the resistance to water ingress may inhibit wateringress, resulting in less rebound mitigation and/or stability.Conversely, as the aperture area approaches an inferior surface area ofthe vehicle, the stabilization and impact attenuation advantages may bereduced, and/or structural loads requirements may disadvantageouslyincrease the resulting mass of the system. Accordingly, in someexamples, utilizing aperture sizes/area(s) within the aforementionedranges may improve overall stabilizer performance in terms of stability,rebound mitigation, impact attenuation, and/or anotherfunctionality(ies).

The shape of apertures can be: round, rounded (e.g., slot or rectanglewith rounded ends), circular, elliptical, slotted, polygonal (e.g.,rectangular), arcuate (e.g., serpentine, arcuate edges, etc.),trapezoidal (e.g., convex trapezoid shape), annular, and/or aperturescan have any other suitable shape or geometry. For example, theapertures can include a plurality of meridional slots.

Apertures can be distributed symmetrically (e.g., rotationally symmetryabout a central axis; mirror symmetry abound a midsagittal plane; etc.),asymmetrically, evenly spaced between support/mountings structure (e.g.,ribs of the stabilizer and/or vehicle; mounting points; etc.; an exampleis shown in FIG. 10B), and/or can be otherwise arranged. Apertures arepreferably distributed/arranged radially relative to the central axisand/or radiate outward relative to a nadir of the stabilizer (e.g.,lowest point along the central axis; extending meridionally).

In variants, apertures can define a characteristic length relative tothe generatrix of the inferior surface of the stabilizer and/or a linesegment thereof (e.g., for a rotation of the generatrix centered along amaximum dimension of the aperture, etc.), which can be: less than 0.1 m,0.1 m, 0.25 m, 0.5 m, 0.75 m, 1 m, 1.5 m, 2 m, 2.5 m, 3 m, 5 m, greaterthan 5 m, less than 10% of a generatrix path length, 25% of a generatrixpath length, 40% of a generatrix path length, 50% of a generatrix pathlength, 60% of a generatrix path length, 70% of a generatrix pathlength, 80% of a generatrix path length, 90% of a generatrix pathlength, greater than 90% of a generatrix path length, any open or closedrange bounded by the aforementioned values, and/or any other suitablecharacteristic length(s).

In variants, apertures preferably define closed geometries/regions(e.g., convex curve) along the surface of the stabilizer, but canadditionally or alternatively define open geometries/regions, for whichthe stabilizer at least partially bounds the aperture. For example, theset of apertures can include one or more apertures at a periphery(a.k.a., lip) of the stabilizer. Apertures at the periphery of thestabilizer can be circular and/or annular (e.g., the vehicle exteriorproviding the radially inward aperture boundary and the stabilizerdefining the radially outward aperture boundary; fully circumferentialabout the vehicle and/or primary axis) or may be partiallycircumferential about the vehicle (e.g., where an open curve or set ofedges of the stabilizer abuts the vehicle exterior, cooperativelydefining a closed geometric region. Additionally or alternatively,apertures may extend up to the periphery of the stabilizer.

In a first example, each of a plurality of apertures extend through athickness of the stabilizer. In the first example, the stabilizer can bemounted with the peripheral edge offset from the vehicle to define acircumferential aperture (between the stabilizer and the vehicle) alongthe peripheral edge, wherein the set of apertures includes the pluralityof apertures and the circumferential aperture.

In a second example, a plurality of apertures radiate outwards relativeto a nadir end of the stabilizer and extend to a periphery of thestabilizer (e.g., in a radial cross section, the apertures are radiallyoffset from the stabilizer by a first portion of the stabilizergeneratrix and span a remainder of the stabilizer generatrix;meridionally).

In a third example, the set of apertures can include a first set ofapertures and a second set of apertures, wherein the first set ofapertures are arranged radially inward of the second set of aperturesrelative to the central axis.

However, the stabilizer can include any other suitable set of apertures.

The stabilizer is preferably rigidly mounted to the vehicle via a set offasteners (e.g., pin clevis, threaded fasteners, etc.), but canadditionally or alternatively be integrated into the structure of thevehicle (e.g., welded, bonded, body elements commonly fabricated in acomposite layup, etc.), removably mounted to the vehicle (e.g., viamechanical fasteners), semi-rigidly mounted to the vehicle (e.g., viaflexible/movable tethers), deformably mounted to the vehicle (e.g., viaa suspension system; via an elastically and/or plastically deformableimpact attenuator; etc.), and/or can be otherwise mounted to thevehicle. The stabilizer is preferably mounted below the vehicle and/orat an inferior end of the vehicle along a primary/vertical axis, withthe stabilizer arranged beneath the nadir end of the vehicle (e.g.,below a nadir of the vehicle body and/or cabin). In an example, thestabilizer can reduce structural (pressure) loads on impact and directimpact loads away from the skin of the vehicle (e.g., on the inferiorsurface; directing loads to the frame).

As an example, when deployed as part of an aerospace balloon vehicle,the stabilizer can be mounted to the vehicle capsule prior to launch(e.g., during balloon inflation, on the deck of a ship, prior to alaunch from a dry launch system, etc.) and can be removed from thecapsule upon retrieval (e.g., which may facilitate servicing, cleaning,drainage, drying, salt removal, etc.).

In variants, the stabilizer can be mounted with the upper and/orperipheral edge of the stabilizer at least partially offset from thevehicle exterior to form a set of peripheral apertures. As an example,peripheral apertures may be advantageous during initial water ingress tofacilitate displaced air venting/egress, which may avoid excess aircompression/pressurization within the interior of the stabilizer fromrestricting or inhibiting water inflow in some circumstances (e.g., anexample of air venting during landing is shown in FIG. 7B). Additionallyor alternatively, the peripheral edge can increase hydrodynamic drag(e.g., resisting rebound motions; acting as a sea-anchor; scooping waterthrough the stabilizer during upward and/or lateral velocity/motion;etc.). Additionally or alternatively, air venting, air egress, and/orair depressurization can occur through the vehicle body, through thethickness of the stabilizer (e.g., via a set of vents), and/or throughany other suitable passive or active air venting/depressurizationmechanism(s). Alternatively, the stabilizer can be mounted incircumferential abutment with the vehicle body (e.g., forming a closededge which encircles the primary axis), and/or the stabilizer can beotherwise mounted.

The stabilizer is preferably a composite structure (e.g., carbon fiber),such as formed (e.g., via layup) from a matrix material (e.g.,polyester, epoxy resins) and a reinforcing material (e.g., glass mat,woven fabric, etc.), but can additionally or alternatively includemetal/alloyed reinforcing structures (e.g., ribs, support rings, flangesand/or reinforcement elements, etc.; steel alloy, aluminum alloy,titanium alloy, etc.), high thermal conductivity materials (e.g.,copper, thermal interface materials, integrated heat sink, high thermalconductivity materials, etc.), high temperature materials (e.g., heatshielding), and/or any other suitable materials/structures. Thestabilizer is preferably a unitary body (e.g., formed, bonded, fastenerassembly, etc.; pre-preg and/or laminated composite layup over a foamcore), but can additionally include multiple bodies which are configuredto be separately mounted/retained relative to the vehicle (e.g., set ofindependently-mounted body panels/wedges, etc.), and/or can be otherwiseconstructed.

In a first set of variants, an example of which is shown in FIG. 5 , thestabilizer 200 can include: a set of ribs 210, a body 220, an optionalsupport ring 230, an optional nadir cap 240, and/or any other suitableset of components.

The ribs 210 can function to mount the stabilizer to the vehicle and/orstructurally reinforce the body 220, transmitting structural loadsbetween the body and the vehicle (e.g., vehicle frame and/or ribsthereof). The ribs are preferably metal (e.g., aluminum alloy), formedwith a superior surface in the shape of the generatrix of thestabilizer. Each rib is preferably configured to mount to acorresponding rib of the vehicle (e.g., with 1:1 correspondence and/oralignment), however the ribs can be otherwise configured. The ribs arepreferably uniformly distributed about the central axis (e.g., uniformradial spacing; meridional ribs) and/or are substantially symmetricabout the central axis. However, the stabilizer can include any othersuitable set of ribs, the ribs can be integrated into the structure ofthe vehicle (or vehicle frame), and/or the stabilizer can be otherwiseconstructed.

The body 220 preferably functions to form the geometric surfaces of thestabilizer which can achieve various fluid dynamic effects (e.g.,stability, impact attenuation, rebound mitigation, etc.). Additionallyor alternatively, the body functions to form and/or define the apertures202. The body is preferably composite, but can additionally oralternatively be formed from aluminum and/or any other suitablematerials. The body can be unitary, can include a plurality of separateelements (e.g., connected to one another, connected via the ribs and/orany other suitable supporting/connective structures of the stabilizer;separately connected to the vehicle; meridional, ‘wedge-shaped’ panelsspanning between adjacent ribs and/or sets of multiple ribs, etc.),and/or can be otherwise configured. In a specific example, the body 220is cone-shaped about a primary axis of the stabilizer. However, thestabilizer can include any other suitable body(ies) defining any othersuitable aperture(s).

The stabilizer can optionally include a support ring 230 which functionsto connect the ribs and/or body (panels) proximal to a nadir end. Forexample, the support ring can be a metal structure (e.g., aluminumalloy) configured to transmit forces/moments between the ribs. As anexample, a support ring may be structurally advantageous, particularlyin various off-nominal load cases (e.g., where the primary/central axisis skewed relative to a gravity vector, such as may occur when landingunder prevailing wind). As a second example, a support ring may beadvantageous to facilitate the use of a nadir cap which is separatelyfabricated from the body (e.g., separate layups; simplifying tooling;etc.). However, the stabilizer can include any other suitable supportring, a support ring and nadir cap can be integrated into a singlestructure or assembly, and/or the system can otherwise altogetherexclude a support ring(s).

Additionally or alternatively, the stabilizer can include any othersuitable reinforcing structures/elements. In particular, aperturesand/or material relief within the body of the stabilizer may reduce thestiffness of the stabilizer, which may result in excess deformationand/or material yield under some load cases. The structural influence ofthe apertures may generally grow increasingly pronounced as the size(e.g., individual area, total combined area, meridional length, etc.)increases. Accordingly, some variants can include integrated flanges(e.g., internal flanges, external flanges, etc.) and/orcircumferential/peripheral reinforcement to stiffen the stabilizerand/or body thereof along the apertures (e.g., flange within a layup orunibody composite, etc.). For example, flanges may reduce stressconcentrations along the edges of the apertures and/or increase thestiffness along aperture edges. Additionally or alternatively, variantscan incorporate multiple smaller aperture arrays (e.g., series ofapertures along a meridional line; array of multiple smaller apertureswithin a body panel, etc.; an example is shown in FIGS. 10A-10B; anexample is shown in FIG. 11 ) in place of a single aperture, which mayimprove the relative strength and/or stiffness of the stabilizer (e.g.,as a function of the aperture area and/or total relief area, etc.).

The stabilizer can optionally include a nadir cap 240 which functions toform the geometric surfaces of the stabilizer (in conjunction with thebody). In particular, where the body forms a portion of the inferiorsurface geometry of the stabilizer, the nadir cap can form a remainderof the inferior surface geometry (e.g., closing out the nadir end).Additionally or alternatively, the nadir cap can provide an additionalstructure (e.g., separate from the body) at a point of impact (e.g.,nadir and/or adjacent structure), which may allow for additionalreinforcement and/or modularity. In a specific example, the nadir capcan include a dome structure at the nadir. The nadir cap is preferablyfabricated separately from the body 220, by the same manufacturingprocess/materials, but can alternatively be fabricated with differentmaterials and/or via a different manufacturing process. The nadir capcan be integrated with the body (e.g., bonded, etc.) and/or separatelymounted to the ribs 230 and/or support ring 240. However, the stabilizercan include any other suitable nadir cap, the nadir cap can beformed/integrated with the body of the stabilizer, or the stabilizer canaltogether exclude a stabilizer cap.

However, the system can include any other suitable stabilizer.

In some variants, the stabilizer can be removable and/or separate fromthe vehicle in one or more configurations, and/or can be otherwisedeployed in any other suitable contexts.

In some variants, the system can include a single (unitary) stabilizer,or a plurality of stabilizers (or stabilizer elements). For example, thesystem can include a single cone-shaped stabilizer, a cone-shapedstabilizer including multiple separate (and/or separately-mounted)elements, and/or a plurality of cone-shaped stabilizers (e.g., eachextending along a respective axis of a vehicle, such as along the axisof each of a plurality of legs, floats/pontoons, pylons, etc.).

In some variants, the stabilizer can optionally include access panels(e.g., an example is shown in FIG. 11 ) and/or a removable cap, whichcan function to facilitate cleaning and/or drainage of the stabilizer.In particular, seawater landings may result in salt deposition and/orseawater collection within the stabilizer interior, which may be washeddown/cleaned after landing (e.g., with or without removal of thestabilizer; on the deck of a launch vessel, etc.; where salt buildup maybe corrosive and/or otherwise negatively impact vehicle longevity).Additionally, variants can optionally include additional orifices (e.g.,at the cap section) to facilitate drainage, and/or may otherwise managefluid collection/rejection below the apertures.

Additionally, variants can optionally include sensor mounts and/orsupport a sensor payload within the stabilizer interior. For example,vehicle sensors, antennas (e.g., GPS, cellular bluetooth, etc.), cameras(e.g., oriented towards Earth; nadir camera;), localization sensors,LIDAR, Radar, sonar, and/or any other suitable sensor(s) can be mountedto and/or integrated with the stabilizer and communicatively coupled tothe vehicle. Sensors can be mounted internally (e.g., within theinterior of the stabilizer, such as within the domed portion of thecap), entirely enclosed within the stabilizer, optically connected to avehicle exterior through a thickness of the stabilizer (e.g., by anintegrated lens), extend through a thickness of the stabilizer (e.g., anexample is shown in FIG. 12B), substantially aligned with anorifice/cavity of the stabilizer (e.g., at a cap portion, an example isshown in FIG. 12A; which may facilitate seawater drainage when drydocked, supported onboard a launch vessel, airborne, etc.), and/orotherwise packaged within the stabilizer. However, the stabilizer canalternatively exclude sensors, sensor payloads can be selectivelymounted and/or removed, and/or the system can be otherwise configured.

In one example, seawater can be drained via sensor orifices, removal ofa cap (e.g., at the nadir end and/or domed portion), and/or a set ofaccess panels. Alternatively, seawater can be otherwise evacuated and/orthe vehicle can be otherwise configured.

In one example, a downward facing (external) camera at a nadir end ofthe stabilizer may facilitate viewing/imaging of a landing site/region(or water impact area) prior to impact, which may facilitate vehiclenavigation and/or collision avoidance in some circumstances.

However, the system can include any other suitable components.

4. Variants

In one variant of a water landing, the vehicle/system can approach thewater with an initial (entry) velocity prior to water impact (e.g., anexample is shown in FIG. 7A). As the vehicle penetrates the surface ofthe water, the vehicle water ingresses the stabilizer and the vehicledecelerates (e.g., an example is shown in FIG. 7B), reducing thedownward velocity until the vehicle slows to a halt (e.g., stationary;vertical velocity component is zero) at some maximum depth (e.g., anexample is shown in FIG. 7C; below a draft depth, an example of which isshown in FIG. 8 ; etc.), where the net upward force on thevehicle/system is large (e.g., maximum buoyant force upwards). Thevehicle/system then accelerates upwards due to the resulting net upward(buoyant) force, while the water within the stabilizer creates acounteracting hydrodynamic drag (e.g., reducing the upward acceleration;damping the ‘spring-like’ buoyancy response; an example is shown in FIG.7D; etc.). Additionally, hydrodynamic drag from the stabilizer candampen ‘spring-like’ buoyancy responses to perturbations of the systemabout the draft depth (e.g., while the vehicle is water-borne; as aresult of waves, wind effects, etc.), stabilizing the vehicle/system atthe draft depth.

In some embodiments, the vehicle includes a cabin (e.g., configured tocontain occupants and/or cargo) and a stabilizer (e.g., as shown in FIG.1 and FIG. 6 ), such as structure protruding from the vehicle (e.g.,arranged at or near a nadir of the vehicle). The structure can be aconical or pseudo-conical structure (e.g., as shown in FIGS. 2 and/or3A-3B), or can be any other suitable structure.

In variants, the stabilizer preferably functions to provide stability tothe vehicle after and/or during a water landing. For example, thestabilizer can define an internal chamber open to the surroundingenvironment (and/or operable to be opened to the surroundingenvironment) via one or more apertures (e.g., as shown in FIGS. 3A-3B),which can allow water to enter the chamber during and/or after a waterlanding (e.g., as shown in FIGS. 7A-7D). The water entering the internalchamber can function to move the vehicle's center of gravity downward,thereby increasing vehicle stability as it floats in the water. In someexamples, rapid flooding of the internal chamber during water landingmaybe preferable, as in the absence of flooding (or with only partialflooding after a threshold time), buoyancy provided by the internalchamber could cause the vehicle to capsize (e.g., tip to the side, suchthat the internal chamber is not submerged or substantially notsubmerged; turn turtle, such that the nadir of the vehicle pointssubstantially upward, etc.) or yield steep roll angles relative to thecabin deck. Additionally or alternatively, the stabilizer (e.g., afterflooding of the internal chamber) can optionally function as a dampingwater drag device, thereby reducing the roll and/or pitch of the vehiclein the water. In some variants, the aerospace capsule and the conicalstabilizer cooperatively define a draft depth (e.g., relative to waterand/or sea water, for a given cargo load), wherein the conicalstabilizer is configured to attenuate water impacts by: penetratingambient water below the draft depth; and damping oscillation about thedraft depth via hydrodynamic drag.

Additionally or alternatively, the stabilizer can optionally function toprovide mechanical assistance during vehicle landing, such as waterlanding. In some examples, the stabilizer can function to prolong (e.g.,as compared with a vehicle with no stabilizer and an otherwise similarstructure) the deceleration time when the vehicle enters the water uponlanding (e.g., wherein part or all of the vehicle becomes submerged inthe water upon landing), thereby decreasing the peak decelerationexperienced by the vehicle/capsule during such a landing (e.g.,decreasing landing shock and shock loads). Additionally oralternatively, the stabilizer can function to deflect the peak waterloads from the lower part of the cabin exterior.

In some variants, the stabilizer can additionally or alternativelyoperate as a sea-anchor (e.g., substantially rigid and/or non-deformablesea-anchor, with fixed geometry) when submerged/flooded.

In some variants, the stabilizer can be a flooding splash cone.

However, the aerospace vehicle and/or method of use can additionally oralternatively include any other suitable elements and/or have any othersuitable functionality.

Alternative embodiments implement the above methods and/or processingmodules in non-transitory computer-readable media, storingcomputer-readable instructions. The instructions can be executed bycomputer-executable components integrated with the computer-readablemedium and/or processing system. The computer-readable medium mayinclude any suitable computer readable media such as RAMs, ROMs, flashmemory, EEPROMs, optical devices (CD or DVD), hard drives, floppydrives, non-transitory computer readable media, or any suitable device.The computer-executable component can include a computing system and/orprocessing system (e.g., including one or more collocated ordistributed, remote or local processors) connected to the non-transitorycomputer-readable medium, such as CPUs, GPUs, TPUS, microprocessors, orASICs, but the instructions can alternatively or additionally beexecuted by any suitable dedicated hardware device.

Embodiments of the system and/or method can include every combinationand permutation of the various system components and the various methodprocesses, wherein one or more instances of the method and/or processesdescribed herein can be performed asynchronously (e.g., sequentially),concurrently (e.g., in parallel), or in any other suitable order byand/or using one or more instances of the systems, elements, and/orentities described herein.

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the preferred embodiments of the invention withoutdeparting from the scope of this invention defined in the followingclaims.

We claim:
 1. A vehicle system comprising: a balloon; a capsule tetheredto the balloon and defining a primary axis; and a stabilizer mounted tothe capsule, the stabilizer defining: an inferior surface comprising ablunt nadir end and a truncated conical surface which is substantiallyradially symmetric about the primary axis; and a plurality of apertureswhich extend through a thickness of the stabilizer.
 2. The vehiclesystem of claim 1, wherein the capsule comprises a cabin which isfluidly isolated from an ambient exterior.
 3. The vehicle system ofclaim 2, wherein a floor of the cabin is substantially orthogonal to theprimary axis, wherein the balloon is tethered at an upper end of thecapsule, opposite the stabilizer along the primary axis.
 4. The vehiclesystem of claim 3, wherein a width of the capsule is larger than amaximum width of the stabilizer.
 5. A vehicle system comprising: anaerospace capsule defining a primary axis; and a conical stabilizermounted beneath the capsule, the conical stabilizer defining a pluralityof apertures which extend through a thickness of the conical stabilizer.6. The vehicle system of claim 5, wherein the conical stabilizercomprises a blunt nadir end along the primary axis.
 7. The vehiclesystem of claim 5, wherein the set of apertures are substantiallyradially symmetric about the primary axis.
 8. The vehicle system ofclaim 7, wherein the set of apertures comprises a plurality ofmeridional slots.
 9. The vehicle system of claim 5, wherein the conicalstabilizer comprises a composite body supported by a plurality of ribs,the ribs mounted to the aerospace capsule.
 10. The vehicle system ofclaim 9, wherein the plurality of apertures comprises at least oneaperture between each adjacent pair of ribs of the plurality of ribs.11. The vehicle system of claim 5, wherein the conical stabilizercomprises an internal flange surrounding each aperture.
 12. The vehiclesystem of claim 5, wherein a superior surface of the conical stabilizerdefines a fluid interior between the conical stabilizer and theaerospace capsule, the plurality of apertures fluidly coupling the fluidinterior to an ambient exterior.
 13. The vehicle system of claim 5,wherein a lip of the conical stabilizer, distal the blunt nadir end, isoffset from the aerospace capsule.
 14. The vehicle system of claim 13,wherein the offset between the lip of conical stabilizer and theaerospace capsule defines at least one aperture at the lip, wherein theconical stabilizer defines a fluid manifold between the plurality ofapertures through the thickness of the conical stabilizer and the atleast one aperture at the lip.
 15. The vehicle system of claim 5,further comprising a set of vehicle sensors extending through the bluntnadir end of the conical stabilizer.
 16. The vehicle system of claim 5,wherein the plurality of apertures defines an aperture area between 2%and 10% of an area of an inferior surface area.
 17. The vehicle systemof claim 5, wherein a generatrix of the stabilizer is smooth andcomprises at least one inflection point.
 18. The vehicle system of claim5, wherein the aerospace capsule comprises a cabin deck which issubstantially orthogonal to the primary axis.
 19. The vehicle system ofclaim 5, wherein the conical stabilizer is configured to operate as bothan impact attenuator and a sea-anchor.
 20. The vehicle system of claim5, wherein the aerospace capsule and the conical stabilizercooperatively define a draft depth, wherein the conical stabilizer isconfigured to attenuate water impacts by: penetrating ambient waterbelow the draft depth; and damping oscillation about the draft depth viahydrodynamic drag.